When using medical treatment apparatuses, as in the area of laboratory analysis equipment, fluid systems with hoses, connectors, bags, pumps, chambers etc. are frequently used.
Thereby, regularly a first fluid flowing through a main channel of the fluid system, usually a liquid, for example blood, dialysis fluid or infusion solution, is sampled. Likewise it is common to dose a second fluid, for example a treatment liquid, a medication or similar into the first fluid. Both cases demand reclosable access points in the fluid system, which are in practice commonly called “ports.”